Ventilation interfaces are used for various applications. One such application involves current treatments for sleep apnea. Sleep apnea is a common sleep disorder characterized by sustained pauses in breathing during sleep. The disorder occurs in both infants and adults. Each episode, known as an apnea, can last more than ten seconds and results in blood oxygen desaturation. A clinical diagnosis of sleep apnea is defined as five or more episodes per hour. There are three types of sleep apnea: central, obstructive, and complex.
Obstructive sleep apnea (OSA) constitutes the most common form of sleep apnea. OSA is a medical condition that includes repeated, prolonged episodes of cessation of breathing during sleep. During a period of wakefulness, the muscles of the upper part of the throat passage of an individual keep the passage open, thereby permitting an adequate amount of air (which contains oxygen) to flow to the lungs. During sleep, the throat passage narrows due to relaxation of the muscles. In individuals having a normal sized throat passage, the narrowed throat passage remains open enough to permit a sufficient level of oxygen to flow into the lungs. However, in individuals with smaller sized throat passages, the narrowed throat passage prohibits adequate amounts of oxygen to flow into the lungs.
In addition, an obstruction, such as a relatively large tongue, an occlusion in the upper respiratory track or an odd-shaped plate can also prohibit a sufficient amount of oxygen to flow to the lungs—thus also resulting in OSA. OSA can result in a variety of medical conditions including daytime drowsiness, headache, weight gain or loss, limited attention span, memory loss, poor judgment, personality changes, lethargy, inability to maintain concentration and/or depression.
Other medical conditions can also prevent individuals, including adults and infants, from receiving an adequate amount of oxygen to the lungs. For example, an infant who is born prematurely can have lungs that are not developed to an extent necessary to receive adequate amounts of oxygen. Further, prior to, during, and/or subsequent to certain medical procedures and/or medical treatments, an individual can be unable to receive an adequate amount of oxygen. Under these circumstances, it is known to use a ventilation interface to apply a positive pressure to the throat of the individual, thereby permitting an adequate amount of oxygen to flow into the lungs.
In known ventilation interfaces, oxygen and/or room air containing oxygen is delivered through the mouth and/or nose of the individual. The most common form of positive pressure treatment for OSA is use of a continuous positive airway pressure (CPAP) device. A CPAP device forces a pressurized breathable gas into the patient's respiratory track and allows air to pass the obstruction(s) and/or occlusion(s). Other forms of positive pressure delivery exist, such as bi-Level positive airway pressure (BiPAP) in which a relatively higher positive pressure is maintained during inspiration and a relatively lower positive pressure is maintained during expiration, and intermittent mechanical positive pressure ventilation (IPPV) in which a positive pressure is applied when apnea is sensed (i.e., the positive airway pressure is applied intermittently or non-continuously). With all these types of therapy, a positive pressure device (i.e., flow generator) connects via a ventilation tube to a ventilation interface. The interface connects to either the patient's nose, mouth or both orifices.
Various interfaces have been developed for positive pressure, and more specifically CPAP therapy. These include various shaped full-face masks, nasal masks, nasal prong masks, oral masks and hybrid masks (i.e., those masks that combine masks such as having an oral cavity with nasal prongs). Nasal prongs offer one popular form of interface for use with CPAP therapy because they are relatively small, less bulky and more comfortable for many patients to wear for long periods of time.
Nasal prongs can generally be separated into two types: nasal pillows and nasal inserts. Nasal pillows typically abut against the openings of a user's nares when in use and may not be inserted substantially within the nasal passages. Nasal inserts are typically positioned within the nasal passages of a user and may or may not abut against the nasal openings. Embodiments and the principles thereof are contemplated for any nasal prong and the like, as will be readily recognized by one having ordinary skill in the art. Nevertheless, for illustrative purposes in a non-limiting manner, exemplary embodiments are described below in reference to nasal pillows.
A seal is maintained between the patient and the ventilation interface through use of headgear. More specifically, the headgear of a nasal pillow assembly creates an upward force by compressing the nasal pillows onto the nasal openings. This compression should be sufficient to effectuate the seal without creating discomfort to the patient. These nasal pillow systems, unlike nasal mask and full-face mask interfaces, help reduce the risk of patients feeling claustrophobic while being treated for OSA through CPAP therapy. However, one issue with nasal pillows is that they have to be calibrated and properly fitted to maintain an effective seal between the interface and patient, while still being comfortable to wear for long periods of time.
Various forms of nasal pillow and headgear assemblies have been developed which attempt to address these design criteria. Two initial examples of nasal pillow interfaces found in the prior art include U.S. Pat. Nos. 5,724,965 and 6,431,172. Both nasal pillow systems require multiple part construction for the reservoir that includes both a hard plastic first component and a softer second component. Thus, the gas reservoir requires at least two parts, which leads to various connecting points that can leak. Moreover, both these prior art systems require complicated headgear, which increases the risk of the patient feeling claustrophobic. Moreover, these designs are complicated, difficult to calibrate and fail to allow easy adjustment by the patient during use.
While more recent commercially available nasal pillow designs continue to provide alternative headgear and connection systems to calibrate the reservoir proximate to the patient's face, these systems still have several drawbacks. Two such examples are the ResMed® Swift LT and the Fisher & Paykel® Opus™ nasal pillows. Both require a two part cannula comprised of: a rigid frame that connects with the ventilation tube and a second more pliable silicone base that has the nasal pillows.
The Swift LT interface includes a ratchet system, which can rotate and lock at various positions relative to the headgear to adjust the angle of the nasal pillows to the patient's face. Since the axis of the ratchet system is well below the nasal pillows, the nasal pillows move in an arc relative to the axis. Therefore, any rotational adjustment undesirably impacts how the user wears the headgear, and consequently forces the user to recalibrate and make further adjustments to the interface and headgear to achieve a proper fit. Also, the toothed part of the ratchet system (which connects to the reservoir) is made of a soft rubber or silicone elastomer, which invariably will degrade and lead to stripping—thus inhibiting the ability to angle the pillows relative to the headgear and effectuate an effective seal between the nares and the patient. Moreover, the complicated design requires a significant level of time and attention to adjust.
The Opus™ nasal pillow does not include a means at all to adjust the angle of the pillows relative to the headgear and therefore the user's face. There are several other drawbacks to both the ResMed® Swift LT and the Fisher & Paykel® Opus™ nasal pillows. Neither product allows the user to quickly disconnect the cannula or to disconnect the cannula while maintaining the headgear in place. Also, both products require extra parts to provide the adequate pillow sizes required to fit different patients.
Accordingly, there is a need in the art of ventilation interfaces for a nasal prong that allows for more simplified construction and that includes an effective means for adjusting and calibrating the interface in relation to the patient to ensure long term comfort. In addition, there is a need in the art for an improved headgear that can connect to the interface to allow a patient to easily assemble, disassemble, adjust and position the interface to ensure an effective seal with the nares. Finally, there is a need in the art to simplify the nasal prong offerings without compromising sealing and comfort. In short, the design should allow more comfortable long term use, require less assembly and be easily calibrated.